damage on bottom of q45

[ttownq45]

I ran over a huge rock in the road was on the other side of a hill ....... Looks like damage to exhaust system on bottom the rear left muffler and right after the catalytic converter.... everytime I give the car gas it sounds like a card in the spokes of bicycle. I'm sure i've damaged the part that secure the mufflers etc... any idea about cost of the repair just a ball park?